The Swift Programming Language - Beginning Swift Games Development for iOS - page 260

enum DaysOfTheWeek: Int {
case Sunday = 0, Monday, Tuesday, Wednesday, Thursday,
Friday, Saturday
}
You define each member of an enum using a case . Notice the way you are defining your
members. You have a comma-separated list with only the first member being set. If the
type of the enum is an Int raw value (raw values are the values you assign to an enum
member), then you have to set only the first value and Swift will determine the remaining
values. To see how this enum is used, copy it and the following snippet into your
main.swift and run it:
var today = DaysOfTheWeek.Friday
println("Today is \(today.rawValue).")
You will see the following output.
Today is 5.
Notice println() in the second line. You are invoking the toRaw() method on the
enum . This function is a built-in function of every enum that will return whatever the raw
value of each member of the enum has stored as its value.
You can use other raw values such as String s and Float s, but you will have to expli-
citly set each value.
enum RGBColors : String {
case Red = "Red", Green = "Green", Blue = "Blue"
}
If an enumeration does not have a meaningful raw value, then you don't have to assign it a
value at all. Each member of the enum will have a value assigned to it by Swift.
enum RGBColors {
case Red, Green, Blue
}
Another nice thing about Swift enumerations is that they can have methods associated
with them. Take a look at the new DaysOfTheWeek enumeration: